• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2010년도 춘계 학술논문 발표대회 1부
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• pp.95-97
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• 2010

This study revealed unusual weather phenomena by comparing and analyzing monthly average temperature and amount of snowfall for the past 10 years, and, based on the weather phenomena, analyzed damage cases of concrete structures in winter. As a result, the temperature for the recent one year became greatly low compared with the monthly average for the past 10 years, and the snowfall increased by 4-5 times compared with the past, so that the frost damage of concrete structures also greatly occurred. Accordingly, in case of concrete construction, because there may occur various variables owing to abnormal weather conditions, it is required that thorough quality control should be performed even from the stage of construction plan, execution and maintenance.

• 대한토목학회논문집
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• 제32권5B호
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• pp.267-272
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• 2012

기후변화로 증가하는 홍수피해를 대처하기 위해 여러 예측 방법들이 개발되고 있다. 홍수예측의 가장 핵심 요소는 홍수예측을 위한 수문모델의 입력자료로 사용하는 강우에 대한 정확하고 신속한 예측이다. 기존의 레이더 강우를 이용한 Nowcasting 보다 더 많은 대응시간을 확보할 수 있는 중소규모의 기후모델인 WRF(Weather Research Forecast)-ARW(Advanced Research WRF)를 소개하고, 이를 한반도 중부지방의 청미천 지역에 적용하려 한다. WRF-ARW의 적용기간은 2006년 7월 11일부터 7월 23일까지이며 이 결과를 청미천 유역에 있는 강우 관측소들(생극, 삼죽, 설성)의 실제 강우관측소의 관측 값과의 비교에 의해 이 강우 사상에 대해 Thomson scheme(미세물리)와 Kain-Frisch scheme(적운형 매개변수)의 조합이 청미천유역에서 가장 적합한 기후물리 조합이며 Mean Absolute Relative Error를 통해 세 개의 강우관측지점이 0.45 이상의 값을 나타내었다.

• 대기
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• 제27권4호
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• pp.467-481
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• 2017

A correction method of reflectivity in partial beam blockage (PBB) area is suggested, which is based on the combination of digital terrain information and self-consistency principle between polarimetric observation. First, the reflectivity was corrected by adding the radar energy loss estimated from beam blockage simulation using digital elevation model (DEM) and beam propagation geometry in standard atmosphere. The additional energy loss by unexpected obstacles and non-standard beam propagation was estimated by using the coefficient between accumulated reflectivity ($Z_H$) and differences of differential phase shift (${\Phi}_{DP}$) along radial direction. The proposed method was applied to operational S-band dual-polarization radar at Jindo and its performance was compared with those of simulation method and self-consistency method for six rainfall cases. When the accumulated reflectivity and increment of ${\Phi}_{DP}$ along radial direction are too small, the self-consistency method has failed to correct the reflectivity while the combined method has corrected the reflectivity bias reasonably. The correction based on beam simulation showed the underestimation. For evaluation of rainfall estimation, the FBs (FRMSEs) of simulation method and self-consistency principle were -0.32 (0.59) and -0.30 (0.57), respectively. The proposed method showed the lowest FB (-0.24) and FRMSE (0.50). The FB and FMSE were improved by about 18% and by 19% in comparison to those before correction (-0.42 and 0.70). We can conclude that the proposed method can improve the accuracy of rainfall estimation in PBB area.

• International Journal of Internet, Broadcasting and Communication
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• 제12권1호
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• pp.130-136
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• 2020

There are many problems that occur currently in agriculture industries. The problems such as unexpected of changing weather condition, lack of labor, dry soil were some of the reasons that may cause the growth of the plants. Condition of the weather in local area is inconsistent due to the global warming effect thus affecting the production of the crops. Furthermore, the loss of farm labor to urban manufacturing jobs is also the problem in this industry. Besides, the condition for the plant like air humidity, air temperature, air quality index, and soil moisture are not being recorded automatically which is more reason for the need of implementation system to monitor the data for future research and development of agriculture industry. As of this, we aim to provide a solution by developing IoT-based platform along with the irrigation for increasing crop quality and productivity in agriculture field. We aim to develop a smart garden system environment which the system is able to auto-monitoring the humidity and temperature of surroundings, air quality and soil moisture. The system also has the capability of automating the irrigation process by analyzing the moisture of soil and the climate condition (like raining). Besides, we aim to develop user-friendly system interface to monitor the data collected from the respective sensor. We adopt an open source hardware to implementation and evaluate this research.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1081-1082
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• 2008

Photovoltaic (PV) power generation system has been widely studied as a clean and renewable power source. The purpose of this study is to keep the output power of photovoltaic cells maximum under any weather conditions. There are so many MPPT (Maximum Power Point Tracking) methods. P&O method has been used as a key MPPT method, both voltage and current coming out from PV array have to be feedback in the method. Thus, the system has a complex structure, and may fail to track MPP of PV array when unexpected weather conditions happen. In order to reduce the feedback components, POS MPPT control method was proposed by the authors. In this paper, the authors apply the POS MPPT control method to three phase PCS system. And the effectiveness of the proposed control scheme is demonstrated through PSCAD/EMTDC simulation.

• 한국해안해양공학회지
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• 제12권1호
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• pp.11-18
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• 2000

1997년 11월 25일 겨울철에 남해안에서 이례적으로 남쪽으로부터 전파되는 높은 파고가 관측되었다. 4m 정도의 이러한 이상 파고는 시간차를 두고 마라도, 부산 그리고 울릉도 순서로 각각에 설치한 파고계에 관측되었으며 특히 서귀포항 공사 중에 발생하여 큰 피해를 입혔다. 겨울철에 발생하는 이상 남파는 저기압의 이상 발달 및 이동으로 인한 것으로 추측되며 이를 살펴보기 위하여 일기도 및 수치모델에 의한 파랑장의 분포 등을 조사하여 그 발생 가능성에 대하여 연구하였다. 앞으로도 겨울철에 발생할 수 있는 이러한 이상 남파에 대한 주의를 요한다.

• Agribusiness and Information Management
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• 제4권1호
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• pp.13-23
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• 2012

Understanding climate change is not only complex but also extensive. Humanity has never embarked on such a huge challenge of trans-national scope: a problem that began in the past continues now and will be continuing for a long time in the future. Nepalese have also significantly felt the impact of global climate change. The scenarios of climate change indicate that the increased temperatures will cause snow-melt which will result in floods, droughts, and uneven weather patterns. The impact of such unexpected climate hazards and weather patterns have already been felt and will continue to be felt in Nepal. These climate change-induced hazards and risks particularly threaten the agriculture sector, which results in food insecurity and makes poor and vulnerable people face increasingly unanticipated impacts to their lives and wellbeing. This paper explores the climate vulnerability of the Nepalese in terms of their physical, social, economic and primarily agricultural losses due to the increasing impact of climate change. The paper argues the need for a timely adaptation of measures to maintain an environment suitable for agriculture and for the well-being of the population residing in the area.

• Nuclear Engineering and Technology
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• 제53권1호
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• pp.244-252
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• 2021

Wind plays an important role in cases of unexpected radioactive pollutant dispersion, deciding distribution and concentration of the leaked substance. The accurate prediction of wind has been challenging in numerical weather prediction models, especially near the surface because of the complex interaction between turbulent flow and topographic effect. In this study, we investigated the characteristics of atmospheric dispersion of radioactive material (i.e. ¹³⁷Cs) according to the simulated boundary layer around the HANARO research nuclear reactor in Korea using the Weather Research and Forecasting (WRF)-Mesoscale Model Interface (MMIF)-California Puff (CALPUFF) model system. We examined the impacts of orographic drag on wind field, stability calculation methods, and planetary boundary layer parameterizations on the dispersion of radioactive material under a radioactive leaking scenario. We found that inclusion of the orographic drag effect in the WRF model improved the wind prediction most significantly over the complex terrain area, leading the model system to estimate the radioactive concentration near the reactor more conservatively. We also emphasized the importance of the stability calculation method and employing the skillful boundary layer parameterization to ensure more accurate low atmospheric conditions, in order to simulate more feasible spatial distribution of the radioactive dispersion in leaking scenarios.

• 천문학논총
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• 제38권3호
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• pp.111-123
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• 2023

In this study, quantitative analysis is attempted on data collected from Chilgapsan Observatory Star Park in Cheongyang-gun, Chungcheongnam-do. The aim of this experimental study in which quantitative analysis of the Astronomical Science Museum in Korea is conducted is to investigate its current situation and secure basic data. As of July 31, 2023, it has had 283,931 cumulative visitors in total. It had the largest number of visitors when it opened (2009 year), after which their number reduced steadily until the pandemic (COVID-19, 2020-2022). Recently, however, the number of visitors has increased. Generally, the number of visitors is highest in August (20.8%) and least in April (4.1%). The visit rate is higher on weekends (Saturday and Sunday) than on weekdays (Monday-Friday), and groups comprise only about 5.3% of the total number of visitors. Moreover, it can be confirmed that the number of visitors increases sharply during events. Finally, it was confirmed that the visit rate was unaffected by weather conditions. Considering these results, we propose the following strategies: 1) Establish a special program that reflects "the weekend effect." 2) Prepare a plan to attract group visitors during the weekdays using "the event effect." 3) Arrange alternative programs (e.g., experiential activities) that can be conducted indoors regardless of weather conditions. We think that our findings will help establish a roadmap for the direction the Astronomical Science Museum should take and aid in preparing a strategic foundation to preemptively respond to unexpected situations (e.g., pandemics).

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2007년도 정기학술발표대회 논문집
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• pp.567-570
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• 2007

최근의 이상기후현상은 지구온난화에 의한 것으로 전 세계적으로 많은 영향을 미치고 있으며, 모든 산업분야에서 이슈가 되고 있다. 우리나라도 지구온난화로 인해 기후변화를 겪고 있으며, 건설 산업 또한 이러한 영향으로부터 자유로울 수 없다. 그러나 아직까지 건설 분야에서 이와 관련한 연구는 미미한 실정이다. 따라서 이에 대한 필요성을 인식 하고 현재 수준을 파악하기 위해, 본 연구에서는 지구온난화가 건설업에 미치는 영향 중 건설공기부분에 초점을 맞추어 분석하였다. 그 결과 지구온난화로 인한 기후변화에 따라 철근콘크리트 공사의 작업불능일의 변화추이를 살펴볼 수 있었고, 이를 토대로 지구온난화가 건설 공기에 미치는 영향의 일부를 파악할 수 있었다. 본 연구는 향후 기후와 함께 변화하는 국내 건설 산업의 미래를 예측하고, 이에 대응하기 위한 기초자료로 활용될 수 있으리라 기대된다.